/* SQUIB - Scala's Quirky User Interface Builder 
    Copyright (C) 2008 Tim Dalton

    This library is free software; you can redistribute it and/or
    modify it under the terms of the GNU Lesser General Public
    License as published by the Free Software Foundation; either
    version 2.1 of the License, or (at your option) any later version.

    This library is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
    Lesser General Public License for more details.

    You should have received a copy of the GNU Lesser General Public
    License along with this library; if not, write to the Free Software
    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA 
*/

import scala.collection.mutable.HashMap 
    
package tfd.scala.squib {

import java.awt.Component
import java.awt.event.{FocusEvent, FocusListener}
import java.util.EventObject

    trait FiresFocusEvents[T <: {  def addFocusListener(fl:FocusListener) }] { self:FiresEventObjects with IdableTrait =>
    self.eventHandlers += (focusEvents _).asInstanceOf[(Object, HashMap[String, EventObject => Unit]) => Unit]

    def focusEvents(comp: T, events:HashMap[String, EventObject => Unit]):T = {
        val handler = new DelegateFocusEventHandler(events);
        if (handler.hasEvents) {
            comp.addFocusListener(handler)
        }
        comp
    }  
  
class DelegateFocusEventHandler(events: HashMap[String, EventObject => Unit]) extends FocusListener {
    private val focusGainedDelegate:Option[FocusEvent => Unit] = events.get("focusgained");
    private val focusLostDelegate:Option[FocusEvent => Unit] = events.get("focuslost");
    
    lazy val hasEvents = !(focusGainedDelegate.isEmpty 
                        && focusLostDelegate.isEmpty)
            
    override def focusGained(fe: FocusEvent) {
        if (!focusGainedDelegate.isEmpty) focusGainedDelegate.get.apply(fe)
    }
    
    override def focusLost(fe: FocusEvent) {
        if (!focusLostDelegate.isEmpty) focusLostDelegate.get.apply(fe)
    }
  }
}
}